1997 BMW 750Li Blown Head Gasket

Engine Mechanical problem
1997 BMW 750Li V12 All Wheel Drive Automatic 140K miles

Hi...my name is Coach tom and I appreciate your website for Q and As...Here is my problem...My son used my '97 BMW and was on the highway with the air conditioning on...he says "it just stopped, so I opened up the Sunroof and kept driving (20 miles) until I smelled rubber..." He pulled over to an offramp gas station and popped the hood, where he ended up finding the fan belts shredded and steam coming out...The water pump went out and was replaced as was the pulley...there was NO damage to the radiator, no leaks, no oil leaking either, and when the engine was started up the Engine Light stayed on as did the Oil light...Upon further examination, it was diagnosed with a blown head gasket...Here's my question: is there anything that temporarily I can use until I can afford to repair the head gasket? It is too expensive right now for me to repair...Your suggestions are welcome and thanks again for this site...Have a great day...Coach tom